Utility boxes, such as electric meter boxes, are typically secured to prevent unauthorized access to the meter. Many of such boxes are secured through the use of split ring that is placed directly around the meter and locked through the use of a barrel lock.
A preferred type of barrel lock for use with the above-described utility boxes is known as a rotating disk barrel lock. These locks include multiple rotating disks that, when rotated into the proper position via a key, will open the lock. An example of such a rotating disk barrel lock is described in U.S. Pat. No. 5,086,631, which is hereby incorporated by reference in its entirety.
Conventional rotating disk barrel locks typically contain a stack of six rotating disks that determine the combination of the lock. In particular, the placement of master disks, each having more than one operational position, within the stack of disks determines the particular combination of the lock and also the number of potential combinations and combination levels for such locks.
The universe of potential combinations is limited, however, in that conventional barrel locks can only accommodate six rotating combination disks. This restricted capacity is the result of industry standards that limit the length of the portion of the barrel lock in which the disks are housed. Indeed, if the lock is not dimensioned in accordance with these standards, it will be incompatible with other standardized lock components, such as lock caps and pad lock seals.
As will be appreciated, users of such locks, typically utility companies and the like, desire their own exclusive combination, or set of combinations, so that a key from one utility cannot open another's lock. Accordingly, a large number of potential combinations is desirable to ensure exclusivity.
In view of the above, it is a general object of the present invention to provide a rotating disk lock mechanism that provides an enhanced number of potential combinations, and combination levels, without increasing the number of rotating disks or the dimensions of the lock. It is also a general object of the present invention to provide a rotating disk lock mechanism in which the combination is not determined exclusively by the number and placement of master disks.